John D. Billings, Hardtack and Coffee: The Unwritten Story of Army Life

Aside from this nervousness under fire, mules have a great advantage over horses in being better able to stand hard usage, bad feed, or no feed, and neglect generally. They can travel over rough ground unharmed where horses would be lamed or injured in some way. They will eat brush, and not be very hungry to do it, either. When forage was short, the drivers were wont to cut branches and throw before them for their refreshment. One m. d. (mule driver) tells of having his army overcoat partly eaten by one of his team --actually chewed and swallowed. The operation made the driver blue, if the diet did not thus affect the mule.

In organizing a six-mule team, a large pair of heavy animals were selected for the pole, a smaller size for the swing, and a still smaller pair for leaders. There were advantages in this arrangement; in the first place, in going through a miry spot the small leaders soon place themselves, by their quick movements, on firm footing, where they can take hold and pull the pole mules out of the wallow. Again, with a good heavy steady pair of wheel mules, the driver can restrain the smaller ones that are more apt to be frisky and reckless at times, and, assisted by the brake, hold back his loaded wagon in descending a hill. Then, there was more elasticity in such a team when well trained, and a good driver could handle them much more gracefully and dexterously than he could the same number of horses.

It was really wonderful to see some of the experts drive these teams. The driver rides the near pole mule, holding in his left hand a single rein. This connects with the bits of the near lead mule. By pulling this rein, of course the brutes would go to the left. To direct them to the right one or more short jerks of it were given, accompanied by a sort of gibberish which the mule-drivers acquired in the business. The bits of the lead mules being connected by an iron bar, whatever movement was made by the near one directed the movements of the off one. The pole mules were controlled by short reins which hung over their necks.